Olivia Newton-John's Longtime Beau Is Missing

Singer Olivia Newton-John’s longtime boyfriend is missing, PEOPLE has confirmed.

Patrick Kim McDermott, 48, went on an overnight chartered fishing trip out of San Pedro, Calif., on June 30 and has not been seen by friends or family since, according to the Coast Guard.

“When McDermott failed to show up at a family event July 6, his kin became concerned,” a Coast Guard statement reads. “The family discovered McDermott’s vehicle, July 11 His personal items were also still on the sport fishing vessel. The family contacted the Coast Guard immediately after this discovery.”

A spokesman for Newton-John told PEOPLE, “Naturally, Olivia Newton-John is extremely concerned about the whereabouts of Patrick McDermott, her very dear friend of many years. She is in close and frequent contact with his family and other friends, as well as with officials who are assisting in this matter.”

Newton-John, who had a longterm off-and-on relationship with McDermott, issued a personal statement to PEOPLE asking anyone with information about the situation to contact authorities.

“I’m hopeful that my treasured friend is safe and well, and I’m grateful to the officials who are working so hard to find Patrick, whom I love very much,” said the Australian star, perhaps best known for her role in the 1978 musical film Grease. ” I ask anybody with information that could help to please, please come forward.”

The Coast Guard Investigative Service asks anyone with information about the case to call 310-732-7344.